This may have been suggested before but I think it would be very helpful to have shops in the frontier so we dont have to run back to the spawn just to go to town to buy something needed
Sorry, but don't 100% see how this would help... And think they might add them in empire's for bases.
I don't think there's a very high chance of someone encountering a shop because of how big the frontier is.
This is definitely something which is likely to be considered when Empires makes its release. Remember: one of the rumored features is the ability to teleport to an outpost. If that were to happen then it would make outposts a lot more accessible.
There acctually used to be shops in the wild back when the first introduced slot shops. They then found a bug and disabled them. However I would totally be in favour of having them back.